Localization of ASC isoforms, NLRP3, and caspase 1. ASC isoforms were transiently co-transfected into HEK293 cells with GFP-tagged NALP3R260W (A) or GFP-tagged pro-caspase 1C285A (B). Cells were fixed and immunostained with polyclonal anti-myc (Santa Cruz Biotechnology) and Alexa Fluor 546-conjugated secondary antibodies (Invitrogen). Topro-3 was used to visualize the nucleus. All images were acquired using laser scanning confocal microscopy with a 100x oil-immersion objective. Panels from left to right show ASC (red), NLRP3 or pro-caspase-1 (green), nucleus (blue), and a merged composite image.